- (void)createPointArc{
    CGFloat raduis = 20;
    CGFloat width = self.bounds.size.width;
    CGFloat height = self.bounds.size.height;
    
    CGContextRef gc = UIGraphicsGetCurrentContext();
    CGContextMoveToPoint(gc, 0, raduis);
    CGContextAddArcToPoint(gc, 0, 0, raduis, 0, raduis);
    CGContextAddArcToPoint(gc, width, 0, width, raduis, raduis);
    CGContextAddArcToPoint(gc, width, height, width - raduis, height, raduis);
    CGContextAddArcToPoint(gc, 0, height, 0, height - raduis, raduis);
    CGContextAddLineToPoint(gc, 0, raduis);
    
    CGContextSetLineWidth(gc, 2.0f);
    [[UIColor redColor] setStroke];
    [[UIColor blackColor] setFill];
    CGContextDrawPath(gc, kCGPathFillStroke);
}